Synchronizing system for electric clocks



Dec. 1, 1931.

C. SOLER SYNCHRONIZING SYSTEM FOR ELECTRIC CLOCKS Filed lay 31. 1930 P r9 (3 v INVENTOR CARLOS SOLER E ATTEORNE;

Patented Dec; 1, 1931 UNITED STATES PATENT OFFICE CARLOS SOLEB, O1 HABANA, CUBA, ASB'IGNOB TO INTERNATIONAL COMMUNICATIONS LABORATORIES, INC., 0! NEW YORK, N. Y., A CORPORATION OF NEW YORK BYNCHBONIZING SYSTEM FOR ELECTRIC CLOCKS Application m d m :1, 19:30. Serial No. 457,934.

This application relates to a method of, and means for, effecting a synchronizing operation over a tele hone circuit, and is more particularly inten ed for use in connection with electric clocks.

Heretofore it has been the practice to synchronize electric clocks over a separate circuit direct from a master clock to the subscriber's clock. The utilization of telephone circuits for the end in view will thus avoid the employment and expense of special circuits for furnishing this service.

The principal object of this invention is I to permit the synchronizing of electric clocks over a telephone circuit by changing certain features t ereof which, while permitting synchronizing impulses to pass, do not interfere with the usual telephone traflic.

A further object is to provide a system wherein a leak or other trouble on the line will be prevented from interfering with the synchronizing impulses being received by the subscribers clock.

A more clear conception of the apparatus, operation and further objects of the invention-may be had from the following description taken together with the accompanying drawing in which:

The figure discloses a circuit embodying the invention.

The master clock is shown at 1 from which a circuit is connected through relay 2 to battery. Relay 2 is operated by impulses from the master clock, thereby alternately opening and closing a circuit from ground and a 100 volt battery. The armature of relay 2 is in turn connected to contact 3 of relay 4 which is the ECG relay in an automatic switching exchange or may be the subscribers cut off relay in a manual exchange. This relay as is well known is connected over conductor 17 to the release trunk brush in the first case,-or to the sleeve in the second case. Contacts 3 and 5 perform their normal functions, name- 1y, connecting ground to the ring of the line and connecting the line relay 6 to the tip. As is well known in the art, contact 3 has ground connected directly thereto. This ground is now under control of relay 2 which,

when operated to connect battery to the line,

subscribers instrument is in use.

removes the ground, and connects the 100 volt battery to the ring side of the line. The operation of relay 2 will not aflfect the operation of the subscribers line switch or circuit, as the 100 volt battery working against the 48 volt telephone battery of opposite polarity will permit 52 volts to be used for the operation of relay 6 under control of the subscribers switch hook. The armatures of relay 4 are connected in a well known manner to the subscribers line which includes the transmitter 7, switch-hook 8 and hell 9. The local circuit for operating the synchronizing mechanism of the subscribers clock is connected to contact 10 which is controlled by the switch-hook 8, thereby preventing synchronizing impulses from passing when the Contact 10 is connected through a resistance 16 to slow release relay 12 which controls, through its make before break contacts, the operation of the clock corrector magnet 13.

It is well known that although a battery leak may be too weak to operate a relay, it may be sufiicient to hold said relay up once it has been operated. Relay 12 has therefore been provided with a make before break contact to insure a momentary impulse through corrector magnet 13, even though relay 12 be held up by a leak. This condition-is rectified when the subscriber removes the receiver from the switch-hook 8, thereby opening the circuit for relay 12 and permitting its release which restores the contacts preparatory to receiving further synchronizing impulses. Also if the subscriber is called but, does not answer. the ringing current will cause the release of relay 12.

Synchronizing impulses from the master clock will operate relay 2 which removes ground from its armature and connects positive 100 volt battery through contact 3 of relay 4 over conductor 14 of the subscribers line to switch-hook 8, contact 10 through the winding of relay 12 to ground, thereby oppulse to the corrector magnet 13. Should the subscriber initiate a call, switch-hook 8 closes the usual circuit through contact 11 and opens the synchronizing circuit just described at crating said relay and transmitting animcontact 10. The impulse circuit is further opened at contact 3 by the operation of relay either on incoming or outgoing calls, and remains open until the call is finished. Ring- 6 ing current will not operate relay 12 because it is slow acting.

It will be apparent from the above description that, as the impulses from the master clock are transmitted preferably on the hour m or half-hour, they do not in any way affect the o ration of either a manual or automatic switc ing tele hone circuit.

' It is also obvious that a grounded wire,

which prevents the passage of synchronizing 15 signals, will be located, by the usual methods known to the telephone art, and repaired at more frequent intervals than in an ordinary clock circuit where the same degree of maintenance is not always feasible.

10 Although the invention has been hereinbefore particularly described in conjunction with the synchronization of electric clocks,. it is to be realized that the operation of relay 12 can be utilized to perform a variety of 2.3 operations such, for example, as the actuation of an audible signalling apparatus at prede termined intervals, or for the synchronization of telegraph apparatus.

What is claimed is:

:so 1. A synchronizing system for electric clocks, comprising a subscribers telephone line, a master clock, a subscribers clock, and a relay connected to the line at said subscribers station, said relay transmitting synas chronizing impulses to said subscribers clock mechanism, said relay having a make beforebreak contact to prevent said mechanism from becoming inoperative.

2. A synchronizing system, comprising a 40 telephone line modified from standard practice by alternately connecting battery of an opposite polarity and ground through the contacts of the cut off relay, a synchronizing relay controlling said alternate connections 45 and thereby transmitting impulses, a sub scribers station, and a slow acting relay connected thereto for receiving and transmitting said impulses to the apparatus to be synchronized.

50 3. A synchronizing system, comprising a telephone line modified from standard practice to include a relay for transmitting impulses, a subscribers station on said line, a

. slow releasing relay connected thereto for res ceiving and transmitting said impulses to the apparatus to be synchronized, and means at said subscribers station for rendering said relay inoperative during periods of telephone use.

In witness whereof, I hereunto subscribe my name this 29th day of May, 1930.

CARLOS SOLER. 

